Acute renal injury (ARI) is a growing clinical problem in critically ill patients and has significant clinical and economic consequences. Some recent studies point to a rising incidence of ARI in the intensive care units over the past several years. Actual evidence suggests there has been some improvement in outcome over time but the mortality associated with ARI remains unacceptably high at around 40%. The consensus-developed definitions of ARI (the RIFLE scale) will be useful for clinical practice in this regard. During the progression of ARI – most frequently caused by severe sepsis as part of multiple organ failure - we can assess two components: the alteration in perfusion and the tubular cell function. Changes in serum creatinine and urine output in a short time period (6–12 hours) give us useful information for the earlier initiation of renal replacement therapy.

        Key words: acute renal failure – sepsis – multiple organ failure – haemofiltration – RIFLE